Influence of Particle Size and Crystalline Level on the Efficiency of Dust Explosion Inhibitors

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• 作者：Diana Castellanos ; Arthur Lewandowski ; Agust铆n Diaz ; Andres F. Mejia ; Victor Carreto ; Chad Mashuga ; Ali S. Rangwala ; Zhengdong Cheng ; M. Sam Mannan
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：July 16, 2014
• 年：2014
• 卷：53
• 期：28
• 页码：11527-11537
• 全文大小：673K
• ISSN：1520-5045

文摘

The influence of size and crystallinity on the efficiency of dust explosion inhibition was systematically studied. We fractionated ammonium phosphate monobasic (MAP, NH₄H₂PO₄) and dibasic (DAP, (NH₄)₂HPO₄) at different size ranges, and we synthesized zirconium phosphate (伪-ZrP, Zr(HPO₄)₂路H₂O) at varying sizes and crystalline levels. To evaluate the inhibitor efficiency of each material, we analyzed the thermal stability of mixtures containing cornstarch and DAP/伪-ZrP/MAP, using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). In addition, the dust explosion severity (i.e., maximum pressure (P_max) and maximum rate of pressure rise ((dP/dt)_max)) of these mixtures was obtained by performing dust explosion tests using a 36 L vessel. The experimental results show that 伪-ZrP provides the highest thermal stability but the lowest rate of heat absorption of the mixtures. DAP exhibited a lower thermal stability in comparison to 伪-ZrP and MAP, but exhibits a remarkable rate of energy absorption during its decomposition reaction. In general, the efficiency of dust inhibitors increased by decreasing particle size. Particularly, DAP and MAP presented a critical diameter (i.e., 128 渭m), where the inhibitor efficiency was enhanced. However, the performance of 伪-ZrP as an inhibitor was not considerably affected by the variation of particle size and crystalline level. Finally, a semiempirical model was developed to identify the factors dominating the reduction of cornstarch explosion severity. In agreement with aforementioned results, the simplified model presents a critical diameter below which the inhibitor efficiency is significantly improved.